.TH std::unordered_multiset::clear 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::unordered_multiset::clear \- std::unordered_multiset::clear

.SH Synopsis
   void clear() noexcept;  \fI(since C++11)\fP

   Erases all elements from the container. After this call, size() returns zero.

   Invalidates any references, pointers, and iterators referring to contained elements.
   May also invalidate past-the-end iterators.

.SH Parameters

   \fI(none)\fP

.SH Return value

   \fI(none)\fP

.SH Complexity

   Linear in the size of the container, i.e., the number of elements.

.SH Example


// Run this code

 #include <iostream>
 #include <string_view>
 #include <unordered_set>

 void print_info(std::string_view rem, const std::unordered_multiset<int>& v)
 {
     std::cout << rem << "{ ";
     for (const auto& value : v)
         std::cout << value << ' ';
     std::cout << "}\\n";
     std::cout << "Size=" << v.size() << '\\n';
 }

 int main()
 {
     std::unordered_multiset<int> container{1, 2, 3};
     print_info("Before clear: ", container);
     container.clear();
     print_info("After clear: ", container);
 }

.SH Possible output:

 Before clear: { 1 2 3 }
 Size=3
 After clear: { }
 Size=0

  Defect reports

   The following behavior-changing defect reports were applied retroactively to
   previously published C++ standards.

      DR    Applied to       Behavior as published              Correct behavior
                       for unordered associative
   LWG 2550 C++11      containers, unclear if complexity  clarified that it's linear in
                       is linear in the number of         the number of elements
                       elements or buckets

.SH See also

   erase erases elements
         \fI(public member function)\fP
